Conventionally, in the apparatus for lifting automobiles for repair, the representative ones of which are those of two-post and four-post types, a vertically-movable carriage connected to a support such as a post has been provided with a pair of swing arms for lifting automobiles which are pivotally connected to the carriage for horizontal or swinging movement. The swing arms may be swung to such horizontal positions as to provide the suitable angle between the two arms for lifting the automobile in a stable manner. Each swing arm is provided with a device for temporarily fixing it in such position lest the swing arm should remove from that position to cause the automobile thereon to drop down during lifting. Many such devices have been proposed, including that disclosed in Japanese Published Examined Patent Application No. 53-3527 "Safety Device for Automobile Support Used for Apparatus for Lifting Automobiles for Repair". However, since the conventional fixing devices have required manual operations for fixing the arms, it has taken much time and trouble to fix them. Also, there were cases where the failure to perform the fixing operations due to carelessness of the personnel resulted in the dropping down of the automobile. Accordingly, the present invention obviates these prior art problems by making automatic the operation of fixing the swing arms.